Hello there; ive recently bought a stilo 1.8 sporting 2005 and the temp gauge never moves.
I suspected the coolant temp sensor and noticed its been taped up as the clip is broken that locks it in. But i also noticed there is only 3 wires coming out of the plug even though its a 4 pin connector is this correct as it should be????

Also if the coolant temp sensor doesnt solve the temperature gauge not moving what else could it be?

Hi, Welcome to the FF.

The 1.8 engine temperature sensor has a 4 pin connector, but only 3 of them are populated. Referring to the diagram below, A1 = Empty, A2 = Red/black. B1 = White, B2 = Orange. Test the resistance of the sensor between pins B1 and B2 with the engine hot and cold.
.

Hi John,

The advice from Darren regarding the wiring is sound.

I would be surprised if it was a fault of the sender itself, these things are usually pretty robust.

The instrument clusters are prone to faults, so it wouldn't surprise me if it was the instrument cluster rather than anything else.

If you have the facility to hook it up to a diagnostic rig, do that and see what the car is reading. This will tell you if the gauge on the car is lying to you or not. If the car reads zero you can be safe it's a wiring issue, maybe sensor issue.

Hello again. Thank you for the replies ive ordered a new sensor and it will be available for collection tomorrow and hopefully i'll get it fitted after i finish work.
Its my girlfriends car and she said the temperature gauge briefly worked on the way to work today lol.
If it is a instrument panel fault is it a case of replacing the whole instrument cluster? Many thanks again guys.

John850t5 said:

Hello again. Thank you for the replies ive ordered a new sensor and it will be available for collection tomorrow and hopefully i'll get it fitted after i finish work.
Its my girlfriends car and she said the temperature gauge briefly worked on the way to work today lol.
If it is a instrument panel fault is it a case of replacing the whole instrument cluster? Many thanks again guys.

Click to expand...

Replacement or repair - yes. Note that the odometer reading (mileage) is stored in the cluster and so would need updating to reflect your vehicles mileage. Note also that a replacement would need a proxy-alignment procedure performing to correctly introduce it to the vehicles CAN computer network - otherwise the odometer reading will flash to show a CAN fault.

repair services are available - including a chap called yellow stilo on here that does repairs very reasonably priced. Not used him personally but comes highly recommended around here.

Given what you've said about worked breifly I'm wondering if it's more of a thermostat issue that sensor.

When you've got the new sensor fitted, turn all the heaters and everything off, leave the car sitting stationary and try to get it to warm up. You're looking for the rubber hose in the top of the engine bay between the radiator and engine block to get quite hot to the touch - don't burn yourself! It should remain cool for quite some time until the stat opens up.

The car should run and maintain a temperature right at the middle mark on the gauge - which should be in the region of 90 degrees. That's running temperature. Even when driving around on these spring afternoons the car should be able to keep at or very close to this 90 degree mark. If it doesnt - stat is failing.

Obviously if you're feeling that these pipes have gotten really rather hot and you're not showing a reading on the guage - you know the gauge or wiring is amiss. You can check the wiring by plugging into diag to see what temperature it shows on diagnostics.

Note also that the fans should kick in at something like 95 degrees - so watch for this and keep your fingers clear!

Artemis thank you for that extensive reply
My plan is to fit the sensor since i picked it up today and see if it does anything but i think you may be correct about the thermostat.

The heaters get warm but never hot at all like you would expect. i assumed though that if a thermostat fails then the car would just simply over heat and not stay cool lol but i am no doubt wrong lol??

I will change the sensor and after that i will feel the coolant pipes at various times whilst the engine is running.

I fitted the coolant temperature sensor and the gauge is working at the moment fingers crossed its all good. But the heaters still dont get fully hot so i will see how it goes for a few days. It got to half way across the temperature gauge and stayed there but i didnt check the heaters once it got this hot i forgot lol ?

You could spin the plastic part of the old sensor while the metal part was secured so i think someone was a bit aggressive with it in the past and broke it

John850t5 said:

Artemis thank you for that extensive reply
My plan is to fit the sensor since i picked it up today and see if it does anything but i think you may be correct about the thermostat.

The heaters get warm but never hot at all like you would expect. i assumed though that if a thermostat fails then the car would just simply over heat and not stay cool lol but i am no doubt wrong lol??

I will change the sensor and after that i will feel the coolant pipes at various times whilst the engine is running.

Click to expand...

Thermostats are "fail safe". So if they are going to fail they should fail in the open position.

You should be able to get the car up to operating temperature (90 deg) as described above by letting it sit idling for long enough. You'll know the thermostat has failed if you go driving around once it's got up to this temperature and the temperature falls right off. It might go down a bit, we're talking 5-10 deg being a bit, but if it drops down towards 70 or less - thermostat is goosed.